PeachParts Mercedes-Benz Forum - View Single Post - Motor quiet with no oil pressure, but loud once it comes?!

JHZR2 · #2 01-21-2004, 01:59 AM

the 617 engine doesnt have hydraulic lifters...

Interesting question though, I dont experience this, so would liek to read replies. I can only think that if the oil flows back, you have metal to metal contact that is continuous, because just the antiwear additives are protecting. Once the oil pressurizes, and things have a film of oil, everything can knock around on its cushion of oil, so instead of continuous contact it is only sporadic, thus the knocking noises.

Or, if the timing chain is tensioned by oil pressure, perhaps when loose and untensioned, something slides, etc., but when tighter, you hear the teeth of the gears hitting each other instead of the chain just flopping onto the teeth?

But thats just a far out late night guess.

JMH